The Three-Eyed Raven, who serves as Bran Stark's (Isaac Hempstead-Wright) mysterious tutor, usually appearing in his dreams, was briefly seen in the season four finale, portrayed by actor Struan Rodger.

Like McShane, whose season six role is currently being kept under wraps, Sydow, who is set to appear in "Star Wars: The Force Awakens," is expected to have limited (but important) screen time in season six.

This isn't the first time "Game of Thrones" has recast a character, as Nell Tiger Free took over the role of Princess Myrcella Baratheon from Aimee Richardson in season five.

One role that definitely won't be recast? Spoiler warning! Jon Snow (Kit Harington), as HBO's president of programming Michael Lombardo is shooting down rumors that the beloved character will return from the dead. "Dead is dead is dead is dead. He be dead," Lombardo told reporters at HBO's 2015 TCA summer press tour session. "Yes. Everything I've seen, heard or read, Jon Snow is dead."